B-Line Eaton series imperial cable tray and ladder, 4" Height, 39" Length, 24" Width, 24" and 12" Tray widths, Series 2-5 horizontal reducing tee, Alu

It's a horizontal tee fitting that branches a cable tray run and reduces at the same time: the main run is 24 inches wide and the branch comes off at 12 inches wide. Rail height is 4 inches, and the fitting bends on a 24 inch radius. Use it where a feeder tray needs to split off a smaller branch tray on the same horizontal plane, rather than cutting and fabricating tray in the field.

Plan for a 39 inch overall length on the fitting with a 24 inch bend radius. That radius is what keeps cable bend limits in check at the branch, but it also means the tee takes up real estate, so check clearance against walls, ductwork and hangers before you set the run. Body width is 24 inches to match the main tray.

The 4A-24-12-HT24 is sold as the fitting itself, model 4A-24-12-HT24. Budget separately for splice plates and hardware at each of the three connection points, plus hangers or trapeze supports on either side of the fitting.

A reducing tee does both jobs in one piece: it branches the run and steps 24 inch tray down to 12 inch in a single 39 inch fitting on a 24 inch radius. The alternative, a full-width 24 inch tee followed by a 24-to-12 reducer section, eats more straight-run length and adds another splice joint to align and bond. Use the reducing tee when the branch is fixed at 12 inches and space is tight.

It's CE marked. That is the only certification carried on the record for the 4A-24-12-HT24, so if your submittal calls for a specific listing beyond that, verify it against the manufacturer's published data for the Series 2-5 aluminum line.